The present invention refers to a control group for directional fins on missiles and/or shells.
In the field of flying objects, such as shells and/or missiles, which during flight can be suitably directed, various solutions are used to be able to vary such a direction.
Currently, the solutions in use in the aforementioned field can summarily be classified hereafter, according to the type of control which is foreseen.
A first example is that consisting of a so-called Cartesian type control.
With this type of control the flying object is equipped with four fin surfaces arranged on opposite sides with respect to a diametral direction of the section of the flying object itself. By moving the first two surfaces and the second two surfaces, which are opposite to each other, in an integral manner the flying object, such as a missile, controls the yawing and pitching movements. The situation is different if the first and the second pair of fin surfaces are moved to oppose each other since in such a way the rolling movement can also be controlled.
In such an arrangement with two pairs of wing surfaces, to carry out the movement of the control surfaces themselves various motors are necessary; more precisely two motors must be foreseen in the case in which the opposite pairs of fin surfaces are joined together, whereas three or four motors must be foreseen in the case in which one wishes to control the individual fin surfaces with control of the rolling axis. Consequently, there is a certain complicatedness of phased arrangement of the motors, a substantial number of which are foreseen.
A second example is that consisting of a so-called polar type control.
With this type of control only two control surfaces are available under the form of fin surfaces and these fin surfaces, according to the plane in which they are arranged, control the yawing and pitching axes of the flying object. In this second case at least two motors are necessary: the first motor which controls the inclination of the control fin surfaces and the second motor which directs the plane of the fin surfaces themselves along the rolling axis.
A third example consists of a so-called mixed type control.
In this case four fin surfaces are arranged, in sets of two of different types arranged successively along the body of the flying object. Therefore, there are two first different consecutive surfaces which move the rolling axis of the flying object, whereas the remaining two different consecutive surfaces are relative to the yawing and pitching movements.
Also in this case at least two motors are necessary to move the aforementioned pairs of control surfaces.
All of these examples for one reason or another have some drawbacks or lackings.
The first example quoted known as cartesian control requires from two to four motors to command the control fin surfaces. Moreover, having four fin surfaces, it has a high aerodynamic resistance.
As for the second example, if on the one hand it has a better aerodynamic penetration, on the down side the manoeuvre thereof takes place in two necessarily successive steps. Indeed, there is a first step in which it is necessary to direct the plane of the control fin surfaces and then a second step which is used to move them in order to direct the flying object. All of this has a negative influence on the response speed of the missile to a command which is sent to it. Moreover, the control system of the first step requires that the servomotors have a relevant torque to direct the plane of the fins along the rolling axis.
Finally, the third example also has the drawback of having two steps in sequence those being the one directing the surfaces and the one for manoeuvre. The presence of these two successive steps slow down its capacity to manoeuvre with respect to the first example. Moreover, with respect to the second example this third example has a higher aerodynamic resistance foreseeing four different fin surfaces.
A main purpose of the present invention is that of specifying a different solution to the aforementioned technical problem which takes account of that which is foreseen by the prior art outlined.
Another purpose is that of realising a control group for directional fins for missiles and/or shells which allows all of the problems previously referred to to be optimised.
Yet another purpose is that of realising a control group for directional fins on missiles and/or shells which has a structure which is extremely simple and even is also not very expensive, still being capable of carry out any one of the tasks assigned to it in an optimal manner.
The last but not least purpose of the present invention is that of realising a control group for directional fins on missiles and/or shells which has a high manoeuvrability to be able to follow targets of any all types in all conditions.
These purposes according to the present invention are achieved by realising a control group for directional fins on missiles and/or shells as outlined in the attached claim 1.
Furhter relevant and special characteristics of the present invention are object of the dependent claims.